Increasing numbers of young homeless people with mental health problems are failing to get adequate support, according to a new report.
Half of those surveyed said they regularly feel depressed
The study found that in London almost three-quarters of homeless people, aged 16-25, had mental health problems.
But the report for the Mental Health Foundation and Centrepoint found a lack of skilled staff resulted in people failing to get the necessary help.
Failure of agencies to work together was also identified as a problem.
Half of those surveyed said they experience regular feelings of anxiety and depression as a result of being homeless.
A fifth had been diagnosed with schizophrenia, bi-polar disorder or clinical depression prior to becoming homeless.
'Making the Link between Mental Health and Youth Homelessness', reported that as a result of these factors "young people often reach crisis point before being seen by a mental health team".
Moira Fraser, of the Mental Health Foundation, said: "We need to see more services working in unison and better pathways to specialist mental health and drug and alcohol services for young homeless people.
"Vulnerable young people asking for help should not have to face long waiting lists or have to cope with services that aren't able to deliver."
Balbir Chatrik, from Centrepoint, said despite the "growing complexity of mental health issues affecting homeless young people... access to mental health services remains limited.
"Our experience shows that it is vital to get services working together in order to provide help before crisis point is reached," she said.